Telephone-receiver.



N. TANNAKA.

TELEPHONE RECEIVER.

APPLICATION FILED SEPT. 30. ms.

Patented Feb. 6, 1917.

WJTJVESSES NAHO TANNAKA, or nnw YORK, N. Y.

TELEPHONE-RECEIVER.

Application filed September 30, 1915.

To all whom it may concern:

Be it known that I, NAHo TANNAKA, a subject of the Emperor of Japan,residing at New York, in the county of New York and State of New York,have invented new and useful Improvements in Telephone- Receivers, ofwhich the following is a full, clear, and exact description.

This invention relates to improvements in telephone receiving apparatus,in which the diaphragms are cushioned and adapted to vibrate more orless bodily or to vibrate simultaneously at the central and outerportions, and in which the diaphragms are placed under the influence ofa plurality of clcctro-magnets disposed cooperatively to act on thecentral and outer portions of the diaphragms.

The main objects of this invention are to provide telephone receiverswhich are faithful in translating electric impulses into audible soundwith least distortion, and to increase the efliciency of the receiversby effectively arranging the electro -magnetic means therein.

With the above and other objects in view, my invention comprises certaindetail of construction and arrangement of parts as will be hereinaftermore fully described, illustrated and claimed.

The invention will be best understood from the following description,taken in connection with the accompanying drawings as reference, forminga part of this specification. However, I desire to-have it understoodthat the apparatus shown herein is merely illustrative, and thattherefore it is not confined to any strict conformity with the showingof the drawings, being susceptible to modifications and changes, or thatsuch changes may be made, when desired, as to fall within the scope'ofthe invention as claimed.

In the drawings, similar numerals indicate similar parts, in which-Figure 1 is a sectional view of a telephone receiver, embodying myimprovements, partly broken away, and Fig. 2 is a similar view of thesame on the line 2-2 of Fig. 1.

Referring to the drawings, the numeral 10 designates a double flangedcup of nonmagnetic metal, which nearly incases all the working parts ofthe apparatus, having an annulus or a ring 11 preferably clamped at themouth. This cup rides by its outer Patented Feb. 6, 1917.

Serial No. 53,442.

flange on the open end of a receiver cell 12 which has exterior screwthreads to be engaged with the interior screw threads of an ear piece orcap 13. By the engagement of a the cell and the cap, the cup 10 with thering 11 is firmly clamped therebetween.

In the flanged portion of the cup, an armature diaphragm 14 is cushionedby washers or cushions 15 and 16 of felt or like material, respectivelyagainst the ring and the shoulder of the cup. The diaphragm is made insuch size as to leave a circular space around its periphery, so that themarginal portions of the cushions will keep it free from directengagement with the casing, viz. the cup with the ring, the peripheraledges of the cushions reaching to the casing.

At the rear side of the diaphragm, a plurality of electro-magnets 17 arearranged around the center. The cores of the electromagnets are clampedor soldered with the branched or subdivided pole of a permanent magnet18, the other pole thereof being brought up toward the central portionof the diaphragm nearly to complete magnetic circuits. Theseelectro-magnets may be of any suitable number, but in Fig. 2, I haveshown a form having four bobbins or coils as a convenient number. Thecoils of the electro-magnets are connected in series in such manner thatwhen a current is sent through all of them, similar poles will appear onthe same side.

The permanent magnet may be composed of several pieces of magnets,polarized and grouped to form a composite marget. In some cases, theemployment of a pair (when there are four bobbins) of horse shoe magnoteis desirable, each to influence two cores, without the centralprojection, the bobbins being accordingly connected. In the claims, bydescribing permanent'magnets I mean a permanent magnet or, magnets inone of such forms above described, regardless of the number and shape ofconstituent magnets.

On the central pole of the magnet 18, is pasted or otherwise secured asoft sheet or washer 19 of sponge rubber or like, whose functions are tocoiiperate with the Washers 15, 16 in holding the diaphragm, andyieldingly to support and balance the same against the magnetic force,particularly when an excess current tends to draw the diaphragm so as tostrike the pole pieces.

The pressure on the cushions or washers 15, 16 is previously adjusted toobtain the best result by varying the thickness thereof and insertingother thin washers, until the diaphragm is under proper pressure at aproper position with respect to the pole pieces.

The terminals of the coils are to be led out as in usual manner tooutside wires through posts 20.

I have illustrated and described herein a receiver having a permanentmagnet in this particular form, but the present improvements are easilyapplicable to direct current and other types of receivers, and the coilsand the magnets may be arranged otherwise suitable, when desired, aswill be readily unders'tood.

A diaphragm, when cushioned as herein set forth, acquires the vibratoryproperty, no matter whether it is elastic or not, because of theelasticity of the cushions. With a diaphragm which is fixed orsubstantially fixed at its peripheral edge, the case is different, asthe'vibratory property is due to the elasticity of the diaphragm itself,and the vibration is almost purely drum-wise.

As the diaphragm 14 is adapted to vibrate more or less bodily (or it isstifl' enough to do so) by virtue of the cushions, it is apparent thatthe influence of the magnets on the whole part of the diaphragm isintegrally effective, and hence the magnets and coils may beadvantageously arranged to act not only on the central portion, but onthe outer portion as well, thereby increasing area of action, but on theother hand, if the diaphragm is clamped at the peripheral edge, this isnot the case.

From the foregoing description, taken in connection with theaccompanying drawings, the advantages of the construction andarrangement of parts and of the method of operation will be readilyapparent to those skilled in the art, to which this inventionappertains.

Having thus described the invention, what I claim as new, and desire toprotect by Letters Patent is:

1. In a telephone receiver, a casing, a diaphragm yieldingly heldtherein by cushions, magnetic means arranged symmetrically so as to urgesaid diaphragm to vibrate integrally in the intended operations, and aresilient washer pressing the central portion of the diaphragm againstthe magnetic force of said means.

2. In a telephone receiver, a casing, a diaphragm cushioned at thefront, back and peripheral edge thereof by soft washers or cushionsunder pressure in the casing, a plurality of electro-magnets arranged toact symmetrically on the diaphragm, and permanent magnets actingdirectly at the center and cooperatively with said electro-magnets atthe outer portion on the diaphragm.

3. In a telephone receiver, a receiver housing, a casing comprising adouble flanged cup and aring cover clamped thereto within said housing,a diaphragm held. between cushions under pressure in the casing, and ayielding lining disposed over the peripheral edge of the diaphragm.

4. In a telephone receiver, the combination with a casing, a vibratorybody, and magnetic means; of a pad disposed over the peripheral edge ofthe vibratory body, and a pliable washer at the central portion of thesaid vibratory body for separating the said body from the magnetic meansagainst the magnetic force.

5. In a telephone receiver, the combination with a casing, a vibratorand magnetic means; of a yielding cushion disposed at the peripheralfront portion of said vi brator, and a resilient Washer at the backcentral portion thereof, holding said vibrator therebetween underpressure, so as to allow said vibrator to vibrate at the peripheralportion thereof under the influence of said magnetic means.

6. In a telephone receiver, the combination with a casing, a diaphragmor other vibrator and magnetic means; of elastic cushions disposed atthe front and side of said vibrator, and a resilient washer disposed atthe central back portion of the same, so as to allow said vibrator tovibrate substantially bodily under the influence of said magnetic means.

7. In a telephone apparatus, a casing, a vibratory plate, a yieldingmounting for said plate embedding the peripheral edge thereof andholding the same under pressure in the casing, and a central washer ofelastic material limiting the vibration of the plate.

8. In a telephone receiver, a mounting for a vibratory plate, comprisingwashers or cushions of yielding material disposed around the peripheraledge portion of said plate forming a collar, and a central washer ofelastic material, as herein set forth.

In testimony whereof I affix my signature in presence of two subscribingwitnesses.

- NAHO TANNAKA. Witnesses:

MIDORI ISHIHARA, James F. I. BURGESS.

